Converting a 1.6 weber carb to a 1.8

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Macc
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Converting a 1.6 weber carb to a 1.8

Post by Macc »

Probably get laughed at but Ive very little mechanical experience (thats changing every day thanks to my mk2!) But in the boxes of parts I obtained with the car theres a 1.6 weber with a manual choke, its the choke i really want so i can replace the "mind of its own" auto!

Anyway, just wondered if it were possible because it looks an exact fit!


1990 MK2 1.8 GTII Scirocco "Black Shuck"
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Re: Converting a 1.6 weber carb to a 1.8

Post by Nate »

Is it a 32/34 dmtl? Usually stamped near the base, or on a little metal flag somewhere. If so, iit is the correct carb, you'd just need to get the appropriate jets for the larger engine from webcon.

If not, the carb might be a tad small. But you could still do it with the right jets, it just would have as much enthusiasm


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Re: Converting a 1.6 weber carb to a 1.8

Post by Macc »

Hi Nate yes its a 32/34 dmtl carb, went on Webcon and im a bit unsure what to get, for instance this but it doesnt say 1.8, 1.6 or anything (but im probably missing it to be honest!) http://www.webcon.co.uk/shopexd.asp?id=15164


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Re: Converting a 1.6 weber carb to a 1.8

Post by Nate »

Ring them ;)


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Re: Converting a 1.6 weber carb to a 1.8

Post by bengould »

As Nate said. Ring them and they will just send you a bag with all the right bits in. After £'s have changed hands of course. :-).


Ben.


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Re: Converting a 1.6 weber carb to a 1.8

Post by Macc »

Rang em up, thoroughly nice chap on the phone, he emailed me the pdf of the instruction manual with all the part numbers required etc so thats one main jet, one air corrector and a gasket (because if I dont order that it will "definitely" need one!)

Part numbers for anyone else doing this are;

73405 (117) Main Jet(Primary), 73405 (127) (Secondary)
77501 (145) Air Corr, 77501 (200)
Primary same as 1.6, Emulsion Tube secondary 61450231 (F33)
9990046200 Gasket

Heres a link to the instructions in case anyone else needs them

https://www.dropbox.com/s/y204um0tq2edc ... 5.pdf?dl=0


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Re: Converting a 1.6 weber carb to a 1.8

Post by Macc »

Aaand not forgetting the base plate conversion and gasket as I did and have just been told by the garage! 99900896 and 99901168


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Re: Converting a 1.6 weber carb to a 1.8

Post by james butler »

have a look at the link in this post on how to tune these carbs.
it will teach you how and why the car behaves the way it does as you tweak bits.
viewtopic.php?f=12&t=18055


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Re: Converting a 1.6 weber carb to a 1.8

Post by 110% »

Thanks for posting the pdf. I've been baffled by my 1.8GTII for a while as I couldn't work out which parts were standard and which were from the weber carb modification that I bought the car with.

My carb flange is knackered, and know I recognise the weber mod, I think I need this 1.6 flange (even though ive got a 1.8) and just add the convertion plates over the top.

https://www.dropbox.com/s/ijvamaiozpda5 ... 7.jpg?dl=0

https://vwheritage.mobi/GB/productDetai ... D=47475232

Could anyone confirm this is correct??


1991 Scirocco MKII - 1.8EX - weber carb
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Re: Converting a 1.6 weber carb to a 1.8

Post by mark1gls »

Looking at your picture it looks like the right part.
I've not got a 1.8 mk2 but a 1.6 mk1 with a FR engine and yours does look the same.


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Re: Converting a 1.6 weber carb to a 1.8

Post by 110% »

Apparently it's an EX engine which would look like this:
http://www.partsbase.org/vw/scirocco-sc ... ke-system/

But the intake looks more like this:
http://www.partsbase.org/vw/scirocco-sc ... arburetor/


1991 Scirocco MKII - 1.8EX - weber carb
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Re: Converting a 1.6 weber carb to a 1.8

Post by 110% »

Actually, is this the flange I need:
https://vwheritage.mobi/GB/productDetai ... D=34024104
And then the two small hex bolts fit into the diagonal holes of this flange with the weber plate over the top. (It says it's for the 1.8 with the 2E2 Pierburg carb which would have once been on it.)
I will have to try and remove the top plate tomorrow to see if this is correct.


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Re: Converting a 1.6 weber carb to a 1.8

Post by 110% »

Just to help anyone else who has a 1.8 GTII weber conversion, this car flange is the one that sits beneath the weber bracket:

https://vwheritage.mobi/GB/productDetai ... D=34024104

And this is the two separated:

https://www.dropbox.com/s/nf6zqjp44ouv9 ... 7.jpg?dl=0

My replacement car flange should arrive tomorrow and then I'm back on the road.


1991 Scirocco MKII - 1.8EX - weber carb
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Re: Converting a 1.6 weber carb to a 1.8

Post by mark1gls »

Glad you have found out which one you need, just make sure when fitting the new one that the carb is not putting extra strain on the flange by sitting at a funny angle and is fixed down properly, there should be a bracket on rocker cover with a grove in it to hold the front of the air box and I think the mk2 may need an extra bit to hold the carb at the right angle but perhaps someone else could confirm this?


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Re: Converting a 1.6 weber carb to a 1.8

Post by bengould »

Yes, the air box mount needs to be raised about 10-15mm. I welded a bit to the top of the original bracket but there is a bit in the weber kit that does the job.

Ben.


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